In today's context, the problem of over population and the resulting need for birth control are becoming very important. Contraceptives have proved their worth to some extent to control this menace. The methods adopted for birth control, which hinder the occurrence of undesirable pregnancy, include the use of condoms, insertion of intrauterine devices, oral contraceptive pills or use of vaginal preparations such as pessaries, gels, foams, creams etc.
All the known methods above however, having certain disadvantages. Among the above said methods the condoms and vaginal pessary causes, uncomfortable feeling in certain cases. Intrauterine devices are free from these disadvantages but, they have to be inserted only by the physician and also give discomfort during intercourse.
The synthetic contraceptive agents available today for fertility control produce severe side effects such as hormonal imbalance, hypertension, increased risk of cancer, weight gain etc. Hence there is a need to replace these agents by safe and effective non-synthetic agents such as plant based contraceptive agents.
There are many plants with reported anti fertility properties in folklore and traditional medicines. Many plants with antifertility activity are known but suitable formulations containing these plants are not available till today. Development of herbal contraceptive drug delivery systems will combine the knowledge of the ancient system of medicine ‘Ayurveda’ and the modern pharmaceutical technologies available today. The development of plant-based anti fertility drug delivery system will provide a user friendly, safe, effective, stable and cost effective herbal formulation that can be used for population control.
Annona squamosa, Family Annonaceae, is grown to a small extent in Assam and is occasionally found in South India. Seeds of Annona squamosa are emetic, astringent, used as a fish poison and are also insecticidal. They possess anti-implantation activity. 50% ethanolic extract of the seeds was found to possess anti-implantation activity after oral administration in rats (Mishra et al, 1979). Crude seed extract of Annona squamosa showed significant growth inhibitory effects on larva of Spodoptera litura (Audrey Leatemia et al, 2001). Anti-head lice activity of a preparation of Annona squamosa seed extract is reported (Ch. Tiangda et al, 1999).
U.S. Pat. No. 4,762,716 describes the process for extraction of pure annonin from the comminuted seeds of Annona squamosa and its use as insecticide.
CN1319424 discloses ethanolic extract of Annona squamosa root bark or tree bark or branch, leaf or seed or their mixture posses' high anticancer activity and low toxicity. However, the spermicidal activity of the extract from the seeds of Annona squamosa has not been so far investigated.
The present invention provides contraceptive gel formulations and dispersible vaginal tablets which comprises effective amount of hydroalcoholic extract from seeds of Annona squamosa along with other suitable pharmaceutically acceptable excipients. Spermicidal activity of the prepared hydroalcoholic extract of the seeds of Annona squamosa was carried out by the inventors of the present invention.
Intravaginal gels have the advantage of being non-irritant, water miscible, water washable, easily spreadable, compatible with the aqueous vaginal environment and miscible with the vaginal fluid. The method employs applying effective amount of hydro alcoholic extract from the seed of Annona squamosa in gel composition in the vagina to prevent conception.
Vaginal tablets are solid dosage forms for vaginal administration. They offer easy placement in the vagina by means of a plastic inserter. They are less messy and easy to handle. Conventional vaginal tablets disintegrate slowly in the vagina and would not be suitable for incorporation of spermicidal agents, which require faster action. However, our present invention deals with fast disintegrating, non-messy, vaginal tablets for spermicidal activity. The method employs inserting fast disintegrating tablets comprising effective amount of hydro alcoholic extract from the seeds of Annona squamosa to prevent conception.